Proficiency Testing in Chemical  Fertilizer Analysis 

Authors

  • Wannarut Chutibut Agricultural Chemistry Group, Agricultural Procuction Science Research and Development Office
  • Jariya Wongtree Agricultural Chemistry Group, Agricultural Procuction Science Research and Development Office
  • Tongchan Pimpet Agricultural Chemistry Group, Agricultural Procuction Science Research and Development Office
  • Chadaporn Khongnam Agricultural Chemistry Group, Agricultural Procuction Science Research and Development Office
  • Omara Hanjavanich Agricultural Chemistry Group, Agricultural Procuction Science Research and Development Office

DOI:

https://doi.org/10.14456/thaidoa-agres.2009.3

Keywords:

proficiency, chemical fertilizer, reference material, homogeneity, Z-score, laboratory

Abstract

The proficiency of    fertilizer   testing     was    conducted    at    the   Agricultural     Chemistry    group,   Agricultural    Production    Science    Research    during     October,   2005- September,   2007.   The   objective   of the    studies    was    to   test   the    proficiency   fertilizer    of   analysis   in   both    public   (governmental)   and   privates    laboratories    and    compatible    utilization    of   standard   of   fertilizer    analysis    qualification   of    quality     assurance of    ISO/ IEC 17025   in    Thailand.   The   study   was   separated     into   two   parts    namely    the   first    one    with   two    compound   fertilizers:  formula   0-52-34   and   12-60-0 (N-P<sub>2</sub>O<sub>5</sub>-K<sub>2</sub> O),   were  prepared  as   the   internal   reference  material  (IRM)  and   statistically assessed   the   homogeneity,   stability  as   well   as   establishing    for     as-signed    value.   Homogeneity   of   the   IRM   was    determined    by    testing    variance    of   one-way   ANOVA  including   outlier,    the    assigned value   of  25  kg   of  the   fertilizer   IRM   was  0 – 51.94 ± 1.14- 35.40 ± 0.83 and   12.09 ± 0.33 – 60.52 ± 1.30 – 0   respectively.   In   the   second   part, the  IRM   samples    were   sent   to   the    fertilizer    analysis    laboratory   in Thailand.   Afterward,   results    from   21    laboratory    participants    comprised   of  13   public   and  8   private    laboratories    were   statistically compared    by    using    Z-score.   The   study   was    found    that   80%  of  laboratory   participants   that    analyzed    ammonium- nitrogen    had    the   satisfactory    results;  16%  and  4%  in   questionable   and  unsatisfactory   results,   in    respective.    In    addition,    for    the    total    phosphate     analysis, 90%   of   laboratory    participants     had    the     satisfied      results and    equally  5%  in    questionable   and    unsatisfactory    results.    For   the    water    soluble     potash     analysis,   53%   of    laboratory    participants      had     the    satisfied     results;   21   and    26%   in    questionable    and     unsatisfied     results     in     respective.   Finally,    these conclusions     were     directly    sent    to    laboratory    participants     and   also    comprised     with     valuable    recommendations.    The   laboratory    participants     that     had     questionable    and    unsatisfactory   results    had     been    collected      and    improved      the     quality    of    analysis     results.    Nowadays,    all    of    these    participants   had     been     successfully     received     the     satisfactory     results.    In addition   to   qualify     internal     quality     assurance    of     fertilizer     analysis.     two kinds    of     reference     materials      were     economically     saving     budget      approximately   10   million     baths.     Furthermore,      these    materials   had     been     distributed    to   3    other     fertilizer     laboratories.

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Published

2009-03-31

How to Cite

Chutibut, W., Wongtree, J. ., Pimpet, T., Khongnam, C., & Hanjavanich, O. (2009). Proficiency Testing in Chemical  Fertilizer Analysis . Thai Agricultural Research Journal, 27(1), 43. https://doi.org/10.14456/thaidoa-agres.2009.3

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Section

Technical or research paper